A pusher vessel adapted for towing by pushing

ABSTRACT

A pusher tug, that is a vessel designed or adapted for towing by pushing, has two downward-extending symmetrical recesses whose surface transversal with relation to the plane of symmetry of the vessel serves as a thrust member interacting with the respective thrust member on the aft end of the pushed vessel.

United States Patent [72] Inventors Boris Vladimirovich Bogdanov ulitsa Mining, 17, kv. 37;

Valery Nikolaevich Starostin, ulitsa Genklnoi, 52. kv. 3; Vitaly lvanovich Erlykin, Moskovskoe shosse, 151, kv. l2,

7 all of Gorky, vU.S.S.R. 211 AppLNo. 191,732 [22] Filed Jan.l6,l969

[45] Patented July 27.1971

[54] A PUSHER VESSEL ADAPT ED FOR TOWING BY rusumc 4 Claims, 4 Drawing Figs.

52] 03.0 114/2351: 51 in. CI B63b 21/00 Primary Examiner-Trygve M. Blix Attorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: A pusher tug, that is a vessel designed or adapted for towing by pushing, has two downward-extending symmetrical recesses whose surface transversal with relation to the plane of symmetry of the vessel serves as a thrust member interacting with the respective thrust member on the aft end of the pushed vessel.

PATENTED JUL2 1 19m FIG.4

' A rusruzn VESSEL ADAPTED FOR rowmc BY, I BUSHING 1 This invention relates to water transportation and more specifically it relates to pusher tugs, that is vessels, designed or adapted for'towing by pushing.

' Widely known in the art are vessels designed or adapted for towing by pushing which havethrust members in the forward end, said members interacting with respective thrust members of the vessel being pushed.

The thrust members in the. bow end of the pusher tug are made in the form of vertical'beams fastened to the bow and protruding forward and sidewa'ybeyond the ship's lines, while the respective thrust members on the aft end of the pushed vessel arehorizontal beams secured to the transom thereof. Such an arrangement of th'ethrust members prevents the pusher and pushed vessels fromv being located close to each other; this results in a large gap, between them, in which a considerable whirling resistance is created. Besides, thethrust members runningfrom 'top to the bottom of the bow end of the pusher tug, almost down -to the waterline, impair the seaworthiness of the pusher tug bow, thus increasing the resistance to the forward motionand jeopardizing other vessels and the pusher itself in the course of mooring and hitching.

' An object of the present inv'ention resides in providing a pusher tug, that is a vessel, designed or adapted for towing by pushing which would decrease the resistance to motion, by bringing this resistance down to that existing in the case of an integral vessel. Another object of the present invention lies in protecting other vessels from being damaged during mooring and hitching by thrust members protruding beyond the ship's lines.

In compliance with theseand other objects a pusher tug is provided, thatis a vessel designed or adapted for towing by pushing, whose forward end has thrust members interacting with thrust members installed on the aft end of the pushed vessel. According to the invention, the bow end of the pusher tug has two symmetrical recesses running from top to the bottom, whose surfaces directed transversally to the ship's plane of symmetry serve as thrust members.

It is expedient, that the lower part of therecesssurface which is transversal to the I shipscenterline be inclined towards the stern. This increases the area of the thrust surface when pushing vessels with different trims.

It is'no less expedient, that the surface of the recess approximately parallel to the ship's 'centerline have a curvilinear profile in its cross section.-Such a shape of the recess surface ensures smooth sliding of the thrust members of the pushed vessel over this surface during rolling.

Given below is a description of an embodiment of this invention with reference to the accompanying drawings, in which:

FIG. I is a side view which shows a bow end of the pusher tug, that is a vessel, designed or adapted for towing by pushing, according to the invention, and the aft end of the vessel being pushed;

FIG. 2 shows a top view thereof, up to the ship's plane of symmetry (the side, which is not shown being symmetrical);

FIG. 3 shows a section taken along line III-III of FIG. 2;

F IG. 4 is a section taken along line lV-'-IV of FIG. I;

' .The conventional forward end of narrowing contour of the rowing contour of the bow,-and as shown in FIG. 3, the recesses disappear at the waterline; thus the recesses do not interfere with normal travel of the vessel in water.

The transversal surface 4 of the recess 2 is a thrust member through which the power, developed by the propulsion machinery of the pusher tug l is transmitted to the pushed vessel 6. Y

The lower part 7 (FIG. 3) of the transversal surface 4 is smoothly sloped towards the stern to allow it to resist the pushing force at different trims of the coupled vessels and to preclude or reduce spraying when the pusher tug sails over rough sea without the pushed vessel. Additionally, as shown in FIG. 3, the part 7 of surface 4 is tapered and narrows downwardly. v I

The longitudinal surface 5 of the recess Zhas a cylindrical shape with a large radius to allow the thrust members of the pushed vessel to slide smoothly. over the longitudinal surface 5 is case of rolling of the coupled vessels. I

The longitudinal surface 5 may be made of two smoothly conjugated surfacesarranged at a small angle to each other.

The pusher tug operates as follows:

The vessels are hitched by bringing the pusher tug I close to the pushed vessel 6. p l

i In case of a straight ahead movement of the coupled vessels, the force of the pushed tug l is transmitted to the pushed vessel via the thrust members 4 and8. v

While the vessels sail against head sea or at different trims of the pusher tug l and pushed "vessel 6, the force of the pusher tug l is applied to the pushed vessel 6 also -via the lower part 7 of the transversal surface 4-;

Under the'conditions of rolling the thrust member of the pushed vessel 6 slides smoothly over the longitudinal surface 5 of the recess 2.

If the vessels are coupled by means of an automatic hitch 9 (shown schematically), located inthe plane of symmetry 3 of the pusher tug 1, the tensile stresses originated in the autor natic hitch by the turning of the coupled vessels will be 30- 40 percent lower than those existing in the currently used thrust members. The reduction of tensile stresses is ensured by a large distance at which the automatic hitch 9 is located from the transversal surface 4 which serves as a thrust element.

The object of the invention is achieved most favorably by providing the aft end of the pushed vessel 6 with two fairings l0 installed on the immersed transom ll of the aft end of the pushed vessel 6. The fairings 10 consist of a framing and a skin, and their outer sides and bottom are made as extensions of the external sides and bottom of the vessel 6 being pushed, while the internal sides serve as guides for the bow end of the pusher tug l.

To widen the area of contact between the vessel 1 being pushed and pusher tug l and to ensure the possibility of towing by pushing in case of vessels withdifferent draft, the aft end of the fairings 10 of the pushed vessel 6 is provided with thrust members 8, extended in height.

It is expedient that the cross section of the fairings 10 be made in the form of a trapezoid with a variable section (as shown in FIG. 4). It is no less expedient that the fairings 10 be partly immersed which will ensure smooth flow of water around the coupled vessels and reduce the resistance to their movement, bringing the value of this resistance close to that of an integral vessel.

The pusher tug, that is, a vessel designed or adapted for towing by pushing, according to the invention, has demonstrated,

during operationaltests both incalm'and rough water that the terms embraces all the equivalent elements functioning,

similarly and employed for the same purposes.

While a specific embodiment of the invention has been disclosed in the description, it will be understood that various modifications and changes within the spirit and the scope of the invention may occur to those skilled in the art.

These changes and modifications can be resorted to without departing from the spirit or the scope of the invention as hereinafter defined by the appended claims.

We claim:

I. In a vessel having a hull with a bow end of conventional narrowing contour, the provision of two symmetrical recesses in the bow end of the hull for engaging the back end of another vessel to be pushed, said recesses extending from the top of the hull downwardly and terminating at the waterline, said recesses gradually diminishing in extent from said top to the waterline so as to disappear at the waterline and thus not interfere with normal travel of the vessel in water, each recess being bounded by transversely and longitudinally extending surfaces, which respectively merge with the narrowing contour of said bow end, the transverse surface of each recess serving as a thrust member for slidable interengagement, during towing, with a thrust member on the aft end of a vessel being pushed.

2. A vessel as claimed in claim 1, wherein the transverse surface of each recess has a lower portion which is inclined towards the stem.

3. A vessel as claimed in claim 1, wherein the longitudinal surface of each recess extends approximately parallel to the diametral plane of the vessel and is curvilinear in cross section.

4. A vessel as claimed in claim 2, wherein the inclined surface of said transverse recess is tapered and narrows downwardly. 

1. In a vessel having a hull with a bow end of conventional narrowing contour, the provision of two symmetrical recesses in the bow end of the hull for engaging the back end of another vessel to be pushed, said recesses extending from the top of the hull downwardly and terminating at the waterline, said recesses gradually diminishing in extent from said top to the waterline so as to disappear at the waterline and thus not interfere with normal travel of the vessel in water, each recess being bounded by transversely and longitudinally extending surfaces, which respectively merge with the narrowing contour of said bow end, the transverse surface of each recess serving as a thrust member for slidable interengagement, during towing, with a thrust member on the aft end of a vessel being pushed.
 2. A vessel as claimed in claim 1, wherein the transverse surface of each recess has a lower portion which is inclined towards the stern.
 3. A vessel as claimed in claim 1, wherein the longitudinal surface of each recess extends approximately parallel to the diametral plane of the vessel and is curvilinear in cross section.
 4. A vessel as claimed in claim 2, wherein the inclined surface of said transverse recess is tapered and narrows downwardly. 